From: Usama Arif <usama.arif@linux.dev>
To: Nico Pache <npache@redhat.com>
Cc: Usama Arif <usama.arif@linux.dev>,
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Subject: Re: [PATCH 7.2 v16 06/13] mm/khugepaged: skip collapsing mTHP to smaller orders
Date: Mon, 20 Apr 2026 08:36:40 -0700 [thread overview]
Message-ID: <20260420153641.215894-1-usama.arif@linux.dev> (raw)
In-Reply-To: <20260419185750.260784-7-npache@redhat.com>
On Sun, 19 Apr 2026 12:57:43 -0600 Nico Pache <npache@redhat.com> wrote:
> khugepaged may try to collapse a mTHP to a smaller mTHP, resulting in
> some pages being unmapped. Skip these cases until we have a way to check
> if its ok to collapse to a smaller mTHP size (like in the case of a
> partially mapped folio). This check is also not done during the scan phase
> as the current collapse order is unknown at that time.
>
> This patch is inspired by Dev Jain's work on khugepaged mTHP support [1].
>
> [1] https://lore.kernel.org/lkml/20241216165105.56185-11-dev.jain@arm.com/
>
> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> Co-developed-by: Dev Jain <dev.jain@arm.com>
> Signed-off-by: Dev Jain <dev.jain@arm.com>
> Signed-off-by: Nico Pache <npache@redhat.com>
> ---
> mm/khugepaged.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
Acked-by: Usama Arif <usama.arif@linux.dev>
next prev parent reply other threads:[~2026-04-20 15:37 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-19 18:57 [PATCH 7.2 v16 00/13] khugepaged: mTHP support Nico Pache
2026-04-19 18:57 ` [PATCH 7.2 v16 01/13] mm/khugepaged: generalize hugepage_vma_revalidate for " Nico Pache
2026-04-20 12:59 ` Usama Arif
2026-04-19 18:57 ` [PATCH 7.2 v16 02/13] mm/khugepaged: generalize alloc_charge_folio() Nico Pache
2026-04-20 13:05 ` Usama Arif
2026-04-19 18:57 ` [PATCH 7.2 v16 03/13] mm/khugepaged: rework max_ptes_* handling with helper functions Nico Pache
2026-04-20 13:15 ` Usama Arif
2026-04-19 18:57 ` [PATCH 7.2 v16 04/13] mm/khugepaged: generalize __collapse_huge_page_* for mTHP support Nico Pache
2026-04-20 13:55 ` Usama Arif
2026-04-19 18:57 ` [PATCH 7.2 v16 05/13] mm/khugepaged: generalize collapse_huge_page for mTHP collapse Nico Pache
2026-04-20 14:20 ` Usama Arif
2026-04-19 18:57 ` [PATCH 7.2 v16 06/13] mm/khugepaged: skip collapsing mTHP to smaller orders Nico Pache
2026-04-20 15:36 ` Usama Arif [this message]
2026-04-19 18:57 ` [PATCH 7.2 v16 07/13] mm/khugepaged: add per-order mTHP collapse failure statistics Nico Pache
2026-04-19 18:57 ` [PATCH 7.2 v16 08/13] mm/khugepaged: improve tracepoints for mTHP orders Nico Pache
2026-04-19 18:57 ` [PATCH 7.2 v16 09/13] mm/khugepaged: introduce collapse_allowable_orders helper function Nico Pache
2026-04-19 18:57 ` [PATCH 7.2 v16 10/13] mm/khugepaged: Introduce mTHP collapse support Nico Pache
2026-04-19 18:57 ` [PATCH 7.2 v16 11/13] mm/khugepaged: avoid unnecessary mTHP collapse attempts Nico Pache
2026-04-19 18:57 ` [PATCH 7.2 v16 12/13] mm/khugepaged: run khugepaged for all orders Nico Pache
2026-04-19 18:57 ` [PATCH 7.2 v16 13/13] Documentation: mm: update the admin guide for mTHP collapse Nico Pache
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